Arthroscopic removal of the meniscus is the most commonly performed orthopedic surgical procedure in the United States. However, it is accepted that the medial and lateral menisci of the human knee play a significant role in force transmission across the knee joint, and that these structures add to the stability of the human knee joint. Long term follow up of total and sub-total meniscectomy demonstrates the early onset of degenerative arthritis of the knee. The long term goal of this study is to design a tissue engineered scaffold that can be implanted at the site of a meniscal resection to prevent the onset of degenerative arthritis associated with meniscectomy. A prototype meniscal replacement, fabricated as a collagen sponge reinforced with biocompatible polymer fibers, has been developed in our laboratory. The hypothesis of this feasibility study is that variation of synthetic fiber density and pattern of distribution in a chemically crosslinked collagen sponge will enhance the mechanical properties, biologic response, and in vivo performance of a tissue engineered meniscus replacement. The specific aims of this study that will test the hypothesis are to: Analyze the effects of fiber density and distribution on the mechanical properties of a tissue engineered meniscus scaffold. Analyze the effects of fiber density and distribution on the biological response to a tissue engineered meniscus scaffold. Choose two scaffolds based on results from mechanical and biological analyses and perform a preliminary in vivo evaluation of the device in a canine model. [unreadable] [unreadable] [unreadable]